Spin Time Questions

[Secular Sanity]

Where did I go wrong?
Let's try it with events..
There are two events .. the first is the light leaving the bottom of the light clock and the second is the light arriving at the top.
In the light clock frame the distance the light travels between the events is ct (distance=velocity x time)
In the observer frame (sees clock moving) the distance the light travels between events is ct'
ct' is greater than ct
If c (the velocity) is the same in both frames * (this is Einstein's wizzo postulate that made him famous)
Divide ct' by c and ct by c
then..
t' is greater than t
or t is less than t' which is where time dilation comes from.
Edit .. this isn't a cause .. this is a symptom. If it wasn't true SR would be wrong.
* this is Special Relativity .. the speed of light  doesn't work the same way as the speed of boats on rivers - it is the same for everyone.

I understand that part. Mr. Homms [I think his name was Stuart…remember him?] explained it quite well, but I thought the sound wave bit was similar.

"These Laws include in particular Maxwell’s Equations describing electric and magnetic fields, which predict that light always travels at a particular speed c, equal to about 3×108 meters per second, that is,186,300 miles per second. It follows that any measurement of the speed of any flash of light by any observer in any inertial frame will give the same answer c."

But in this video, the guy states that we need to make some important distinctions. There are three different phenomena under consideration here, e.g., curvature, gravity and gravitational attraction.

In Newtonian physics, gravity and gravitational attractions are one in the same. However, in GR, gravitational attraction is only an apparent attraction. Gravity and curvature are one in the same. Where you have curvature, you have gravity. Where you have no curvature, you have no gravity and lastly, where you have accelerating frames of reference, you have apparent gravitational attraction. This apparent gravitational attraction is not gravity. It is not space-time curvature.

These two separate phenomena require separate explanations. The equivalence principle tells us that a uniform gravitational field is actually just an accelerating frame of reference.

So far, he hasn't said anything that doesn't line up with what you've said in the past. 

When you’re done with your pond, will you watch this one and explain if or where he gets it wrong?

https://www.youtube-nocookie.com/embed/PjT85AxTmI0

[confused2]

but I thought the sound wave bit was similar.

If we started with twins Alice and Bob - are you seeing any way for Bob to end up physiologically younger than Alice? Not the speed of sound in air thing but actually younger?

I have a debt to be repaid to the people who spent so much time helping me to see it .. would you like me to carry on or quit?

[Secular Sanity]

but I thought the sound wave bit was similar.

If we started with twins Alice and Bob - are you seeing any way for Bob to end up physiologically younger than Alice? Not the speed of sound in air thing but actually younger?

I have a debt to be repaid to the people who spent so much time helping me to see it .. would you like me to carry on or quit?

Not with the riverboat, but if we increase the speed to relativistic speeds, then yes. 

Yes, carry on, please. 

What I’m really interested in the accelerating reference frame and the equivalency principle.

You agree with the last video that I posted, correct?

[Secular Sanity]

I might have figured out where this is all heading. One of the videos credited a paper by Henry H. Lindner as inspiration. Could even be him...I’m not sure, but I’m guessing that it’s going to be some sort of space theory.

http://henrylindner.net/Writings/Lindner...rected.pdf

Edit: Hmm…maybe not because most of their videos have links to other papers and different authors.

If bored, and you see anything fundamentally wrong in any of the videos, let me know, will ya?

Yeah, yeah, I know—you might, and you might not.

Peace out, C2. 

[Secular Sanity]

Note to self→ Someone finally critiqued the acceleration part of the video by tossing in momentum.

He also made a couple of videos on the twin paradox stating that time dilation and length contraction work together. The first postulate of special relativity states that the laws of physics and electromagnetism are the same in any inertial frame of reference. This implies that the experiments performed in stationary and moving inertial frames yield the same results. For the observer on the planet, the time shift was due to time dilation, but for the observer on the spaceship, it was due to the length contraction.

https://www.youtube-nocookie.com/embed/zuKr3TZhTho

Spinning disc→ I still don’t understand how the circumference would shrink without the radius shrinking.

[confused2]

If bored, and you see anything fundamentally wrong in any of the videos, let me know, will ya?

I'm just an SR 101 guy. I don't want to do what I've just asked Kornee to not do - like posting up my favourite ideas. I had a quick look at what Niel De Grasse Tyson had to say about gravity - seemed a bit 'nobody knows'.
The Dialect guy made the point that you can't detect an accelerating lift from a distance and (I think) carried this over to gravity (acceleration) caused by mass .. so not right. Some things work in your own head but not anywhere else. Einstein spent 10 years looking at this.. this needs an rpenner type and I'm just not in his league.

[Kornee]

If bored, and you see anything fundamentally wrong in any of the videos, let me know, will ya?

I'm just an SR 101 guy. I don't want to do what I've just asked Kornee to not do - like posting up my favourite ideas. I had a quick look at what Niel De Grasse Tyson had to say about gravity - seemed a bit 'nobody knows'.
The Dialect guy made the point that you can't detect  an accelerating lift from a distance and (I think) carried this over to gravity (acceleration) caused by mass .. so not right. Some things work in your own head but not anywhere else. Einstein spent 10 years looking at this.. this needs an rpenner type and I'm just not in his league.

Again I don't get your drift re that remark concerning me. What I will say is having noticed another vid by Dialect:
https://www.youtube.com/watch?v=hFlzQvAyH7g
, which just looking at the title obviously follows the false picture of 'BH = river/waterfall' popularized by Andrew Hamilton, I do NOT endorse every thing Dialect tries to wring out of his take on an Aether/Ether theory.
I have previously pointed out a number of reasons why the river/waterfall model necessarily fails logically. That's all I want to add. Have fun between the two of you.

[confused2]

Wild speculation .. I'll post it and come back later to see if I can make any sense of it..
"Close to a mass, for any point, the 'forward' direction in time involves a 'down' in direction." .
As a flat space guy it makes no sense but maybe it will make more (or less) sense if I have a little look at curved space.

[Secular Sanity]

In GR, the total energy of a system is not just the sum of kinetic and potential energy. It includes the energy of the gravitational field, which changes with curvature. The total conservation of energy is conserved if the action is invariant under times translation.

Time translation symmetry—I don’t get it. 

My sarcasm might overshadow my curiosity. I might or might not work on this, but I will order "Emmy Noether's Wonderful Theorem" by Dwight E Neuenschwander.

[confused2]

Emmy Noether is up with Einstein and after occasional attempts to understand her I'd say just as incomprehensible.

Back to Idiotville..

My thought for today concerns the Equivalence Principle.
We are in a rocket coasting along. We place a piece of chalk (hovering) in the air at the front of the rocket so we have literally marked a point in space with chalk. We start the rocket motors and the piece of chalk .. the marked point in space .. ends up at the back of the rocket.
Back on Earth we mark a point in space with a piece of chalk.. when we let go of the chalk the marked point in space ends up on the floor .. exactly like what happened in the spaceship. Unlike the spaceship the Earth doesn't need any fuel to make the trick work so maybe conservation of energy is a red herring.
Assuming the chalk is no more than a marker.. gravity is giving us a coordinate (system) that is continually diving into the Earth. There is an Aether rain type idea which 8 out of 10 cats think is bonkers so I will discard it without further consideration. It is vaguely possible that the coordinate system of the surface of the Earth is rushing up to hit the 'falling' chalk (like the back of the rocket) - unless anyone has any sensible ideas I'll see if I can find any cats with an opinion about this.